Two-anode tube and connection system for the same



P. KAPTEYN Dec. 17, 1935.

TWO-ANODE TUBE AND CONNECTION SYSTEM FOR THE SAME Filed June 14, 1933 v -K t n 740W: m! w Patented Dec. 17, 1935 UNITED STATES PATENT OFFICE TWO-ANODE TUBE AND CONNECTION SYSTEM FOR THE SAME Application June 14, 1933, Serial No. 675,673

In Germany June 1'7, 1932 2 Claims.

An object of the invention is a connection-system comprising a back-coupling and an amplifying circuit and wherein said circuits are entirely independent from each other.

A further object of the invention is an electronic valve adapted for use in such circuits.

Such a valve preferably may consist of an electronic tube having a cathode, a grid, and tWo independent anodes. According to the invention, the one anode, in a known manner, may be con structed in cylindrical form, and the other anode may be in the form of a rod. It is possible to produce the second anode merely from a piece of wire. If the tube according to the invention is furnished with a cathode produced according to the metallic vapour process, the metal to be atomized is preferably secured to the cylindrical anode.

Still further objects of the invention will be understood from the appended drawing, wherein Fig. 1 shows a connection-system according to the invention and Fig. 2 shows a form of embodiment of the electron-valve to be employed in said system In the Fig. 2, I is the glass bulb of the tube, 5 the cathode, 4 the grid, 2 the cylindrical anode and 3 the rod-like anode. For numerous purposes it may be of advantage to provide also a special grid between the first grid and the anodes or between the anodes themselves.

According to the invention, the two-anode tube is employed in feed-back connection in such fashion that back-coupling and amplifying circuits result which are completely independent of each other. In this manner it is possible to obtain much greater amplifications with sufiicient freedom from reactions, i. e., to increase the amplification without impairing the high frequencies.

In Fig. 1 there is shown by way of example a connection system according to the invention. In the same 1 is the two-anode tube having the cylindrical anode 2, the rod-shaped anode 3, the grid 4 and the cathode 5. Connected with the anode 2 is the back-coupling circuit with the resistance II, the condensers 9 and I and the coil 8. Connected with the grid 4 is the input circuit with the condenser l and the coil 6. Connected with the anode 3 is the amplifying circuit with the anode leak resistance I2 and the coupling elements consisting of a coupling condenser I3 of fixed value and a grid leak resistance I4.

Since the back-coupling circuit is completely independent of the amplifying circuit and. no detrimental reaction of the two circuits is existant, the connection elements of these circuits may be selected optimally each for itself in accordance with their peculiarity. For example, the resistance l I may be furnished with a value of approxi- 5 mately 200,000 ohms, the condenser I0 selected at 800 cm., and the condenser 9 at 300 cm. Since the back-coupling circuit with relatively high loading powers possesses merely a small potential amplification, a detrimental reaction is unable to 10 take place.

On the other hand the resistance I2 may readily be selected at 3 megohms and more. In this case a reaction is unable to take place, as the capacity of the rod-like anode is too small.

By employing the tube according to the invention, for example in the connection system as described, it is accordingly possible with the most simple means to separate completely the backcoupling circuit from the amplifying circuit, and in this manner to obtain a considerably greater amplification without increasing the structural means and without loss of high tones. It has been found convenient for numerous purposes of use to link up the grid or the grids arranged between the cathode and the anode or anodes with zero potential, for example by'connection with the cathode itself.

I claim:

1. In a connection system comprising a backcoupling circuit comprising relatively small resistances of the order of 200,000 ohms and an amplifier circuit comprising extremely large resistances of the order of 3 megohms an electron valve comprising one cylindrically shaped anode and one rod-shaped anode, said back-coupling circuit connected to said cylindrically shaped anode and said rod-shaped anode connected to said amplifier circuit.

2. In a connection system comprising a backcoupling circuit comprising an ohmic resistance of the order of 200,000 ohms and a condenser in-the order of 1000 cm. connected in parallel to said ohmic resistance, and an amplifier circuit comprising extremely large resistances of the order of 3 megohms an electron valve comprising one cylindrically shaped anode and one rod-shaped anode, said back-coupling circuit connected to said cylindrically shaped anode and said rodshaped anode connected to said amplifier circuit.

PAUL KAP'I'EYN. 

